1. Field of the Invention
The present invention relates in general to the production of autostereoscopic pictures of the type employing a lenticular screen. More specifically, the invention concerns novel apparatus for composing or projecting such pictures in such a way that uninterrupted and non-overlapping condensed, lineiform images are formed beneath each lenticule of the lenticular screen.
2. The Prior Art
Lenticular screen-type autostereoscopic pictures are produced basically according to two techniques: the direct or "in camera" technique, in which the taking and composing steps are both carried out within the camera, and the indirect technique, in which a number of two-dimensional views of an object field are made from different vantage points and the three-dimensional picture is subsequently composed or projected by projecting the two-dimensional images through a lenticular screen. The present invention has its principal applicability to the indirect technique, so that only this technique will be described hereinafter.
Various advances in the state of the art of the indirect technique are disclosed by Lo and Nims in the commonly owned U.S. Pat. No. 3,953,869. One of these advances and improvements concerns apparatus for expanding the individual, projected, condensed lineiform images so that these images will be contiguous (but do not overlap). This is accomplished by "scanning" the projected image from each two-dimensional frame in a direction transverse to the longitudinal direction of the lenticules. Such apparatus causes the condensed lineiform images to fill the image band beneath each lenticule while permitting the projection of less than w/m images, where w is the lenticule width of the lenticular screen and m is the width of the condensed images.
Although the aforementioned scanning technique affords important advantages for certain applications, it is desirable in some instances to be able to compose stereoscopic pictures without use of the scanning mechanisms associated with that technique. This is particularly true where very short composing times are necessary as, for example, in the manufacture of mass production items such as postcards and the like.